NASA | Looking Down a Well: A Brief History of Geodesy

Geodesy is a field of study that deals with the measurement and representation of the Earth, and it all started when a clever human named Eratosthenes discovered that you could measure the circumference of the Earth by looking down a well. Over time, the field of geodesy has expanded and evolved dramatically, and NASA uses technology like radio telescopes, ground surveys, and satellites to contribute! Learn more about geodesy in this video!